The first task you’re telling the system to only update the yum cache.
On the second you are effectively upgrading all packages to the latest version by using state=latest but you should also use update_cache=yes on the same task to be sure you’re refreshing the cache with its latest package information.
The yum module documentation provides exactly this example:
- name: upgrade all packages
yum: name=* state=latest
After the execution of the task, the terminal should display a message in yellow meaning the status of the task is changed.